Generic expression of a matrix where all coefficients are defined by a functor. More...

#include <CwiseNullaryOp.h>

Inheritance diagram for Eigen::CwiseNullaryOp< NullaryOp, PlainObjectType >:

Public Types
typedef internal::dense_xpr_base< CwiseNullaryOp >::type	Base

Public Member Functions
EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE EIGEN_CONSTEXPR Index	cols () const

EIGEN_DEVICE_FUNC	CwiseNullaryOp (Index rows, Index cols, const NullaryOp &func=NullaryOp())

const EIGEN_DEVICE_FUNC NullaryOp &	functor () const

EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE EIGEN_CONSTEXPR Index	rows () const

Protected Attributes
const internal::variable_if_dynamic< Index, ColsAtCompileTime >	m_cols

const NullaryOp	m_functor

const internal::variable_if_dynamic< Index, RowsAtCompileTime >	m_rows

Detailed Description

template<typename NullaryOp, typename PlainObjectType>
class Eigen::CwiseNullaryOp< NullaryOp, PlainObjectType >

Generic expression of a matrix where all coefficients are defined by a functor.

Template Parameters

NullaryOp	template functor implementing the operator
PlainObjectType	the underlying plain matrix/array type

This class represents an expression of a generic nullary operator. It is the return type of the Ones(), Zero(), Constant(), Identity() and Random() methods, and most of the time this is the only way it is used.

However, if you want to write a function returning such an expression, you will need to use this class.

The functor NullaryOp must expose one of the following method:

`operator()()`	if the procedural generation does not depend on the coefficient entries (e.g., random numbers)
`operator()(Index i)`	if the procedural generation makes sense for vectors only and that it depends on the coefficient index `i` (e.g., linspace)
`operator()(Index i,Index j)`	if the procedural generation depends on the matrix coordinates `i`, `j` (e.g., to generate a checkerboard with 0 and 1)

It is also possible to expose the last two operators if the generation makes sense for matrices but can be optimized for vectors.

See DenseBase::NullaryExpr(Index,const CustomNullaryOp&) for an example binding C++11 random number generators.

A nullary expression can also be used to implement custom sophisticated matrix manipulations that cannot be covered by the existing set of natively supported matrix manipulations. See this page for some examples and additional explanations on the behavior of CwiseNullaryOp.

See also: class CwiseUnaryOp, class CwiseBinaryOp, DenseBase::NullaryExpr

Definition at line 60 of file CwiseNullaryOp.h.